rtphone/src/engine/helper/HL_NetworkFrame.cpp

142 lines
4.0 KiB
C++

#include "HL_NetworkFrame.h"
#include "HL_InternetAddress.h"
#define ETHERTYPE_MPLS_UC (0x8847)
#define ETHERTYPE_MPLS_MC (0x8848)
#define MPLS_STACK_MASK (0x00000100)
#define MPLS_STACK_SHIFT (8)
NetworkFrame::PacketData NetworkFrame::GetUdpPayloadForEthernet(NetworkFrame::PacketData& packet, InternetAddress& source, InternetAddress& destination)
{
PacketData result(packet);
const EthernetHeader* ethernet = reinterpret_cast<const EthernetHeader*>(packet.mData);
// Skip ethernet header
packet.mData += sizeof(EthernetHeader);
packet.mLength -= sizeof(EthernetHeader);
// See if there is Vlan header
uint16_t proto = 0;
if (ethernet->mEtherType == 129)
{
const VlanHeader* vlan = reinterpret_cast<const VlanHeader*>(packet.mData);
packet.mData += sizeof(VlanHeader);
packet.mLength -= sizeof(VlanHeader);
proto = ntohs(vlan->mData);
}
// Skip MPLS headers
if (proto == ETHERTYPE_MPLS_UC || proto == ETHERTYPE_MPLS_MC)
{
// Parse MPLS here until marker "bottom of mpls stack"
for(bool bottomOfStack = false; !bottomOfStack;
bottomOfStack = ((ntohl(*(uint32_t*)(packet.mData - 4)) & MPLS_STACK_MASK) >> MPLS_STACK_SHIFT) != 0)
{
packet.mData += 4;
packet.mLength -=4;
}
}
const Ip4Header* ip4 = reinterpret_cast<const Ip4Header*>(packet.mData);
if (ip4->mProtocol != IPPROTO_UDP)
return PacketData();
switch (ip4->version())
{
case 4:
return GetUdpPayloadForIp4(packet, source, destination);
case 6:
return GetUdpPayloadForIp6(packet, source, destination);
default:
return PacketData();
}
}
NetworkFrame::PacketData NetworkFrame::GetUdpPayloadForSLL(NetworkFrame::PacketData& packet, InternetAddress& source, InternetAddress& destination)
{
PacketData result(packet);
if (packet.mLength < 16)
return PacketData();
const LinuxSllHeader* sll = reinterpret_cast<const LinuxSllHeader*>(packet.mData);
packet.mData += sizeof(LinuxSllHeader);
packet.mLength -= sizeof(LinuxSllHeader);
switch (ntohs(sll->mProtocolType))
{
case 0x0800:
return GetUdpPayloadForIp4(packet, source, destination);
case 0x86DD:
return GetUdpPayloadForIp6(packet, source, destination);
default:
return PacketData();
}
}
NetworkFrame::PacketData NetworkFrame::GetUdpPayloadForIp4(NetworkFrame::PacketData& packet, InternetAddress& source, InternetAddress& destination)
{
PacketData result(packet);
const Ip4Header* ip4 = reinterpret_cast<const Ip4Header*>(packet.mData);
if (ip4->mProtocol != IPPROTO_UDP)
return PacketData(nullptr, 0);
result.mData += ip4->headerLength();
result.mLength -= ip4->headerLength();
const UdpHeader* udp = reinterpret_cast<const UdpHeader*>(result.mData);
result.mData += sizeof(UdpHeader);
result.mLength -= sizeof(UdpHeader);
// Check if UDP payload length is smaller than full packet length. It can be VLAN trailer data - we need to skip it
size_t length = ntohs(udp->mDatagramLength);
if (length - sizeof(UdpHeader) < (size_t)result.mLength)
result.mLength = length - sizeof(UdpHeader);
source.setIp(ip4->mSource);
source.setPort(ntohs(udp->mSourcePort));
destination.setIp(ip4->mDestination);
destination.setPort(ntohs(udp->mDestinationPort));
return result;
}
NetworkFrame::PacketData NetworkFrame::GetUdpPayloadForIp6(NetworkFrame::PacketData& packet, InternetAddress& source, InternetAddress& destination)
{
PacketData result(packet);
const Ip4Header* ip4 = reinterpret_cast<const Ip4Header*>(packet.mData);
if (ip4->mProtocol != IPPROTO_UDP)
return PacketData(nullptr, 0);
result.mData += ip4->headerLength();
result.mLength -= ip4->headerLength();
const UdpHeader* udp = reinterpret_cast<const UdpHeader*>(packet.mData);
result.mData += sizeof(UdpHeader);
result.mLength -= sizeof(UdpHeader);
/*
if (result.mLength != ntohs(udp->mDatagramLength))
return PacketData(nullptr, 0);
*/
source.setIp(ip4->mSource);
source.setPort(ntohs(udp->mSourcePort));
destination.setIp(ip4->mDestination);
destination.setPort(ntohs(udp->mDestinationPort));
return result;
}